Total Ionizing Dose Radiation Effects in Al2O $_{3}$-Gated Ultra-Thin Body In$_{0.7}$Ga$_{0.3}$As MOSFETs

We have investigated total ionizing dose (TID) radiation effects in Al
$_{2}$
O
$_{3}$
-gated ultra-thin body In
$_{0.7}$
Ga
$_{0.3}$
As MOSFETs. A non-monotonic dependence of the threshold voltage
$(V_{\rm th})$
on the X-ray radiation dose was observed and analyzed; the accompanying degradation in subthreshold swing (SS) likely is caused by non-uniform trapped charge in the near-interfacial Al
$_{2}$
O
$_{3}$
rather than interface-trap generation. The off-current and gate breakdown voltage were independent of dose up to 6 Mrad(SiO
$_{2}$
). Compared to the InP-free device, the device with an InP barrier is more vulnerable to TID effects in terms of
$V_{\rm th}$
shift, SS, and mobility degradation.